title: Unraveling a novel transcription factor code determining the human arterial-specific endothelial cell signature.
abstract: Endothelial cells (ECs) lining arteries and veins have distinct molecular/functional signatures. The underlying regulatory mechanisms are incompletely understood. Here, we established a specific fingerprint of freshly isolated arterial and venous ECs from human umbilical cord comprising 64 arterial and 12 venous genes, representing distinct functions/pathways. Among the arterial genes were 8 transcription factors (TFs), including Notch target HEY2, the current "gold standard" determinant for arterial EC (aEC) specification. Culture abrogated differential gene expression in part due to gradual loss of canonical Notch activity and HEY2 expression. Notably, restoring HEY2 expression or Delta-like4-induced Notch signaling in cultured ECs only partially reinstated the aEC gene signature, whereas combined overexpression of the 8 TFs restored this fingerprint more robustly. Whereas some TFs stimulated few genes, others boosted a large proportion of arterial genes. Although there was some overlap and cross-regulation, the TFs largely complemented each other in regulating the aEC gene profile. Finally, overexpression of the 8 TFs in human umbilical vein ECs conveyed an arterial-like behavior upon their implantation in a Matrigel plug in vivo. Thus, our study shows that Notch signaling determines only part of the aEC signature and identifies additional novel and complementary transcriptional players in the complex regulation of human arteriovenous EC identity.
authors.affiliation: Department of Cardiovascular Sciences, Molecular and Vascular Biology Research Unit, Endothelial Cell Biology Unit, KU Leuven, Leuven, Belgium;
authors.forename: Xabier L
authors.initials: XL
authors.lastname: Aranguren
authors.forename: Xabier
authors.initials: X
authors.lastname: Agirre
authors.forename: Manu
authors.initials: M
authors.lastname: Beerens
authors.forename: Giulia
authors.initials: G
authors.lastname: Coppiello
authors.forename: Maialen
authors.initials: M
authors.lastname: Uriz
authors.forename: Ine
authors.initials: I
authors.lastname: Vandersmissen
authors.forename: Mohammed
authors.initials: M
authors.lastname: Benkheil
authors.forename: Joaquin
authors.initials: J
authors.lastname: Panadero
authors.forename: Natalia
authors.initials: N
authors.lastname: Aguado
authors.forename: Alberto
authors.initials: A
authors.lastname: Pascual-Montano
authors.forename: Victor
authors.initials: V
authors.lastname: Segura
authors.forename: Felipe
authors.initials: F
authors.lastname: Prósper
authors.forename: Aernout
authors.initials: A
authors.lastname: Luttun
mesh_terms: D001158:Arteries / Q000166:cytology*; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D002460:Cell Line; D002478:Cells, Cultured; D016000:Cluster Analysis; D042783:Endothelial Cells / Q000378:metabolism*; D053263:Gene Regulatory Networks; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism; D006801:Humans; D008957:Models, Genetic; D020411:Oligonucleotide Array Sequence Analysis; D034622:RNA Interference; D051880:Receptors, Notch / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D059467:Transcriptome
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D051880:Receptors, Notch; D012097:Repressor Proteins; D014157:Transcription Factors; C405693:HEY2 protein, human